Exam 2: Ch 8 Central Nervous System

Question 1

Cerebrum

Answer 1

• largest part of brain (80% of mass)

- and is responsible for higher mental functions

Question 2

Cerebrum consists of

Answer 2

two hemispheres interconnected by tract (white matter in CNS) of the corpus callosum

Question 3

Cerebrum:

 Each hemisphere has 5 lobes

Answer 3

• frontal
• parietal
• temporal
• occipital
• insula (not seen; covered by frontal, parietal and temporal lobes)

Question 4

Cerebral cortex

Answer 4

• outermost portion of cerebrum (3 – 4 mm of gray and underlying white matter)
• with numerous folds and grooves = convolutions

Question 5

 An elevated fold is called a

Answer 5

gyrus

Question 6

 A depressed grove is called a

Answer 6

sulcus

Question 7

 Frontal lobe is separated from

Answer 7

parietal lobe by a deep fissure called the central sulcus

Question 8

 Precentral gyrus of frontal lobe is involved in

Answer 8

motor control

Question 9

 Postcentral gyrus of parietal lobe

Answer 9

receives sensory info. from areas controlled by precentral gyrus

Question 10

 NOTE: the face and hands occupy a larger portion of the sensory and motor cortex than the rest of the body. Why?

Answer 10

Density = number per unit area

Question 11

Temporal lobe contains

Answer 11

auditory centers

- receives sensory info from cochlea

Question 12

 Occipital lobe is responsible for

Answer 12

• for vision

- coordination of eye movements

Question 13

 Insula plays role in

Answer 13

• memory encoding
• integrates sensory info with visceral responses
• coordinates cardiovascular response to stress

Question 14

 X-ray computed tomography (CT)

Answer 14

= involves complex computer manipulation obtained from x-ray absorption of tissues of different densities
- visualizes soft tissues at different depths

Question 15

 Positron-emission tomography (PET)

Answer 15

• uses radioisotopes that emit positrons injected into the blood stream
• positrons collide with electrons causing the emission of gamma rays that can be detected and indicate the most active areas of the brain
• is used to examine brain metabolism and blood flow, drug distribution

Question 16

 Magnetic resonance imaging (MRI)

Answer 16

protons (H+) can be controlled by magnetic fields and emit detectable radio-wave signals when stimulated
- shows brain function

Question 17

 Electroencephalogram (EEG)

Answer 17

Measures electrical activity of cerebral cortex

- used to diagnose epilepsy & brain death

Question 18

 Memory involves

Answer 18

a number of regions in brain and several circuits

Question 19

 Amnesia (memory loss) serves in

Answer 19

studies to reveal how memory works

Question 20

 Declarative memory

Answer 20

ability to remember facts and events

Question 21

 Nondeclarative memory

Answer 21

perceptual and motor skills

Question 22

short-term (S-T) memory

Answer 22

loss of memory of recent events

Question 23

• long-term (L-T) memory

Answer 23

may involve activation of genes

Question 24

 The consolidation of S-T into L-T memory is the function of

Answer 24

the medial temporal lobe (MTL) = hippocampus, amygdaloid nucleus, and adjacent areas of cerebral cortex

Question 25

 Hippocampus is critical for

Answer 25

acquiring new memories & consolidating short- into long-term memory

Question 26

 Amydala is crucial for

Answer 26

fear memories

Question 27

 Removal of the left MTL impairs

Answer 27

the consolidation of short term verbal memories and removal of the right MTL impairs the consolidation of short term non-verbal memories

Question 28

LTP

Answer 28

↑ sustained excitability of a synapse after initial high frequency stimulation

Question 29

• LTP is thought to be a form of

Answer 29

synaptic learning

Question 30

 Neurogenesis in Hippocampus Appears to be crucial for

Answer 30

learning & memory

Question 31

 Hippocampus contains

Answer 31

neural stem cells that may produce new neurons (neurogenesis)

Question 32

 Stress or depression impede

Answer 32

- learning & cause hippocampus to shrink | • Stress reduction & antidepressants return size to normal

Question 33

Hindbrain

Answer 33

- pons - cerebellum - medulla

Question 34

 Pons =

Answer 34

contains several nuclei of cranial nerves and 2 important respiratory control centers = pneustic & pneumotaxic

Question 35

 Cerebellum =

Answer 35

- 2nd largest structure in brain (> 100 billion neurons) - receives input from proprioceptors (joint, tendon, & muscle receptors) - involved in coordinating movements & motor learning

Question 36

 Medulla =

Answer 36

contains all tracts that pass between brain & spinal cord, many nuclei of cranial nerves, several crucial centers for breathing & cardiovascular systems

Question 37

 Reticular formation =

Answer 37

complex network of nuclei & fibers spanning medulla, pons, midbrain, thalamus, & hypothalamus;

Question 38

 Reticular formation = | functions as

Answer 38

reticular activating system

Question 39

 Reticular formation sets level of

Answer 39

arousal of cerebral cortex to incoming sensory information